Archery bow with variable bow-tensioning device

ABSTRACT

An archery bow provided with an internal cavity extending substantially along its entire length. A pair of longitudinally movable reinforcing members are disposed in the cavity for movement therein toward the ends of the bow which are drivingly connected by an actuator having a shaft extending outwardly of the bow to which is secured a knob for rotation of said actuator to move the reinforcing members in opposite directions to thereby adjustably vary the tension force of said bow and thereby vary the force necessary to bend the bow. The bow has a pointer that indicates on a scale the adjusted tension force developed in the bow.

United States Patent Inventor James R. Palma 1502 Curry Road,Schenectady, N.Y. 12306 Appl. No. 39,297

Filed May 21, 1970 Patented Dec. 7, 1971 ARCHERY BOW WITH VARIABLE BOW-Primary Examiner-Richard C. Pinkham Assistant Examiner-William R. BrowneAnomey- Settle and Oltman ABSTRACT: An archery bow provided with aninternal cavity extending substantially along its entire length. A pairof longitudinally movable reinforcing members are disposed in the cavityfor movement therein toward the ends of the bow which are drivinglyconnected by an actuator having a shaft extending outwardly of the bowto which is secured a knob for rotation of said actuator to move thereinforcing members in opposite directions to thereby adjustably varythe tension force of said bow and thereby vary the force necessary tobend the bow. The bow has a pointer that indicates on a scale theadjusted tension force developed in the bow.

ARCHERY BOW WITH VARIABLE BOW-TENSIONING DEVICE BACKGROUND OF THEINVENTION The present invention refers to archery bows for hunting ortarget shooting and more in particular to an archery bow having atensioning device to vary the force required to bend the bow.

Archery bows are normally constructed to provide an elongatedcurvilinear body having a midportion of increased cross section andtapering towards opposite ends to terminate in tip portions which areinterconnected by the bow string. The bow is usually made of a flexiblematerial and the tapered configuration adds to the flexibility of thebow when the bow string is tensioned by the placement of an arrow on thestring.

It is often required to vary the tension of the bow under certainhunting or target shooting conditions. Thus, under certaincircumstances, bows of varying stiffnesses must be used to obtain therequired arrow propelling force.

It is known to adjustably mount the bow string so that its position canbe varied at the tip ends of the bow to thereby increase or decrease theeffective length of the bow adding more stiffness to the bow as thestring is moved towards the center of the bow and increasing theflexibility of the bow as the string is moved further outwardly towardsthe tip ends. However, this arrangement is unsatisfactory in that itforeshortens the arrow string and in that only a limited number ofdefinite positions are available to vary the tension force required tobend the bow.

SUMMARY OF THE INVENTION The present invention provides an archery bowwhich is hollow substantially along its entire length. Slidableelongated reinforcing members are disposed within the bow for movementin opposite directions toward the bow ends to thereby vary the tensionforce required to bend the bow. The elongated reinforcing members areinterconnected at the center of the bow by a rack and pinion mechanismoperable from the outside of the bow. The pinion shaft on the outside ofthe bow is provided with a knob for rotation of the pinion and which hasa pointer to cooperate with a scale or dial to indicate the adjustedtension force.

The tension device of the present invention provides infinite tensionadjustment for an'archery bow by simply turning the knob on the outsideof the bow to the desired position.

The device of the present invention will be best understood by referenceto the following detailed description in connection with the appendeddrawings forming a part thereof.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings illustrate apreferred embodiment of the invention in which FIG. I is a longitudinalcross section through an archery bow embodying the device of the presentinvention;

FIG. 2 is a side elevation of the midportion of the archery bow shown inFIG. I;

FIG. 3 is an enlarged transverse cross section through the midportion ofthe bow in FIG. I showing the actuating mechanism more in detail; and

FIG. 4 is a transverse cross section through the archery bow as shown inFIG. I as seen along line 44 thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to the drawingsan archery bow constructed in accordance with the present invention isshown at comprising substantially identical elongated body portions 12and 14 which are shaped curvilinear and provide a substantially rigidmidportion of increased cross section 16. From the handle or midportionI6 the bow limb members 12 and I4 are tapered in opposite directionstowards the tip portions 18 and 20 respectively. The taperedconfiguration adds to the flexibility of the bow and simultaneouslyuniformly distributes bending stresses along its length.

Each of the opposite body portions I2 and 14 is provided with alongitudinal cavity 22 extending from the midportion 16 16 toward theends 18 and 20 of the bow. It will be understood that, in an assembly,the identical body portions I2 and 14 of the bow will be laminatedtogether along their solid cross sections so as to enclose the cavity22.

A pair of tapered reinforcing members 24 and 26 are disposed within thecavity 22. Each of the reinforcing members 24 and 26 comprises anelongated plate which is tapered toward the tip portions I8 and 20respectively. The reinforcing members 24 and 26 are disposed such as tooverlap at the midportion I6 of the bow. The overlapping ends of thereinforcing members 24 and 26 are each provided with oppositely disposedrack teeth 28 and 30 respectively which face each other.

The reinforcing members 24 and 26 are biased towards each other at themidportion 16 by means of springs 32 and 34, respectively, secured inthe cavity 22 adjacent the sides of the plates 24 and 26 opposite fromthe rack teeth 28 and 30 respectively.

The reinforcing members 24 and 26 are adapted to slide within the cavity22 in opposite directions toward the tip ends of the bow or awaytherefrom towards the midportion. To accomplish this, a pinion 36 isrotatably disposed between the rack teeth 28 and 30 of the reinforcingmembers 24 and 26. The pinion 36 is supported on a pinion shaft 38 whichinner end is joumaied within a boss portion 40 provided in the cavity 22at the midportion 16 of the bow. The pinion shaft 38 extends outwardlyof the bow at one side thereof at the midportion I6 and is providedoutwardly with a knob 42 providing a handgrip for manual rotation of thepinion shaft 38. The knob 42 is provided with a pointer 44 whichcooperates with an indicating means such as a scale or dial 46 providedon the outside of the midportion I6 of the bow. The dial 46 togetherwith the pointer 44 indicates to the bow handler the respective adjustedposition of the reinforcing members 24 and 26 within the bow so as to beable to obtain a correct tension adjustment.

It will be understood that in operation tension adjustment of the bow I0is accomplished by manipulation of the knob 42 on the outside of thebow. Rotation of the knob 42 in one direction causes longitudinalmovement of the reinforcing members 24 and 26 in opposite directionstoward the tip ends 18 and 20 of the bow l0 and rotation of the knob 42in the opposite direction causes longitudinal movement of thereinforcing members 24 and 26, again in opposite directions, toward themidportion 16. If the reinforcing members 24 and 26 are moved outwardlytoward the tip ends 18 and 20 the stiffness of the bow or the tensionforce required to bend the bow will be increased and, conversely, if thereinforcing members 24 and 26 are moved towards each other, i.e. towardthe midportion I6 of the how the stiffness of the bow will be decreased,requiring a lesser amount of tension force to bend the bow.

The reinforcing members 24 and 26 are preferably made of spring steelhaving a desired stiffness against bending.

During assembly the mechanism is preferably lubricated so as to ensure afaultless and foolproof operation of the mechanism and it will beunderstood from the description that the mechanism is completely sealedin in the cavity 22 by laminating the two arrow portions 12 and 14together so as to prevent the entrance of moisture or contaminants intothe cavity 22.

It will be understood from the foregoing description that by the presentinvention an effective tensioning device for an archery bow has beenprovided having a mechanism completely enclosed within said bow and anactuator outwardly of said bow for operation of the mechanism whichcooperates with an indicating means provided on the bow to indicate theadjusted tension force of the bow.

Although the present invention has been described with reference to onlyone preferred embodiment it will be understood that the device issubject to various modifications as may be made by a person skilled inthe art to which the invention pertains and such modifications aredesired to be included within the scope of the appended claims.

lclaim:

1. In an archery bow having a flexible elongated curvilinear bodytapered from the center toward both its ends and a string connectedbetween the ends, the improvement comprising: a handle and bow limbportions having an internal cavity extending from the handle and intothe bow limb portions a substantial distance, a pair of identicaloppositely disposed elongated members disposed within said cavities forsliding movement therein, with respect to each other, towards and awayfrom the said bow limb portions; said members having end portionsoverlapping each other at the center of the cavity in the handle andmeans adjustably connecting said end portions of said members toselectively move said members with respect to each other within saidcavity towards or away from said bow limb portions 2. In the improvementas defined in claim 1, said members comprising plates tapered from thehandle towards the bow limb portions and each of said end portions ofsaid members being provided with rack teeth in facing relationship toeach other 3. ln the improvement as defined in claim 2, said meansadjustably connecting said end portions of said members, comprising apinion disposed for rotation within said cavity between said members formeshing engagement with said rack teeth and means extending outwardly ofsaid bow connected to the pinion for rotation of said pinion so thatupon rotation of said pinion said members will be moved in oppositedirections relative to each other.

4. In the improvement as defined in claim 3, means provided within saidcavity adjacent each of said members for biasing said members towardseach other to retain said rack teeth in engagement with said pinion.

5. In the improvement as defined in claim 3, said means extendingoutwardly of said bow comprising a pinion shaft and a knob, said knobsecured to the pinion shaft for manual rotation thereof.

6. In the improvement as defined in claim 5, further comprisingindicating means disposed on the outside of said handle and positionedadjacent said knob and said knob having a pointer cooperating with saidindicating means to indicate the relative adjusted position of saidmembers within said bow.

7. An archery bow comprising an elongated flexible body, said bodyhaving a rigid midportion, said body being tapered in cross sectiontowards its ends from said rigid midportion; said body having a cavity;body tensioning device comprising: reenforcing means disposed withinsaid cavity in said body and adjustably movable therein toward oppositeends of the body for varying the tension of said body, said reenforcingmeans comprising a pair of overlapping reenforcing members, rotatablemeans between said overlapping reenforcing members connecting saidreenforcing members at said rigid midportion; an actuator for saidrotatable means extending outwardly of said midportion and having a handpiece for manual rotation of said rotatable means, said hand piece beingadapted to move said reenforcing members in opposite directions withrespect to each other upon rotation thereof; said hand piece having apointer and, indicating means disposed on the outside of said midportionto indicate the adjusted position of said reenforcing members.

8. In the device as defined in claim 7, said rotatable means comprisinga pinion disposed within said body cavity at the rigid midportionthereof and between said pair of reenforcing members, said reenforcingmembers being provided with rack teeth facing each other and adapted formeshing contact with said pinion and said actuator comprising a pinionshaft connecting said pinion to said hand piece.

9. In the device as defined in claim 8, the further provision of biasingmeans disposed within said body cavity adjacent each of said members andspaced from said rack teeth so as to continuously bias said memberstowards each other to maintain said rack teeth in meshing engagementwith said pinion.

1. In an archery bow having a flexible elongated curvilinear bodytapered from the center toward both its ends and a string connectedbetween the ends, the improvement comprising: a handle and bow limbportions having an internal cavity extending from the handle and intothe bow limb portions a substantial distance, a pair of identicaloppositely disposed elongated members disposed within said cavities forsliding movement therein, with respect to each other, towards and awayfrom the said bow limb portions; said members having end portionsoverlapping each other at the center of the cavity in the handle andmeans adjustably connecting said end portions of said members toselectively move said members with respect to each other within saidcavity towards or away from said bow limb portions.
 2. In theimprovement as defined in claim 1, said members comprising platestapered from the handle towards the bow limb portions and each of saidend portions of said members being provided with rack teeth in facingrelationship to each other.
 3. In the improvement as defined in claim 2,said means adjustably connecting said end portions of said members,comprising a pinion disposed for rotation within said cavity betweensaid members for meshing engagement with said rack teeth and meansextending outwardly of said bow connected to the pinion for rotation ofsaid pinion so that upon rotation of said pinion said members will bemoved in opposite directions relative to each other.
 4. In theimprovement as defined in claim 3, means provided within said cavityadjacent each of said members for biasing said members towards eachother to retain said rack teeth in engagement with said pinion.
 5. Inthe improvement as defined in claim 3, said means extending outwardly ofsaid bow comprising a pinion shaft and a knob, said knob secured to thepinion shaft for manual rotation thereof.
 6. In the improvement asdefined in claim 5, further comprising indicating means disposed on theoutside of said handle and positioned adjacent said knob and said knobhaving a pointer cooperating with said indicating means to indicate therelative adjusted position of said members within said bow.
 7. Anarchery bow comprising an elongated flexible body, said body having arigid midportion, said body being tapered in cross section towards itsends from said rigid midportion; said body having a cavity; bodytensioning device comprising: reenforcing means disposed within saidcavity in said body and adjustably movable therein toward opposite endsof the body for varying the tension of said body, said reenforcing meanscomprising a pair of overlapping reenforcing members, rotatable meansbetween said overlapping reenforcing members connecting said reenforcingmembers at said rigid midportion; an actuator for said rotatable meansextending outwardly of said midportion and having a hand piece formanual rotation of said rotatablE means, said hand piece being adaptedto move said reenforcing members in opposite directions with respect toeach other upon rotation thereof; said hand piece having a pointer and,indicating means disposed on the outside of said midportion to indicatethe adjusted position of said reenforcing members.
 8. In the device asdefined in claim 7, said rotatable means comprising a pinion disposedwithin said body cavity at the rigid midportion thereof and between saidpair of reenforcing members, said reenforcing members being providedwith rack teeth facing each other and adapted for meshing contact withsaid pinion and said actuator comprising a pinion shaft connecting saidpinion to said hand piece.
 9. In the device as defined in claim 8, thefurther provision of biasing means disposed within said body cavityadjacent each of said members and spaced from said rack teeth so as tocontinuously bias said members towards each other to maintain said rackteeth in meshing engagement with said pinion.